The present invention is directed to the field of tactile codes for the visually impaired and blind, and is more specifically directed to embossed symbols which represent the letters of the alphabet and the Arabic numerals 0-9 which can be traced with the fingertips.
The conventional means for conveying written information to visually impaired or blind persons has long been the braille code. Braille is a tactile code in which each of the letters of the conventional Roman alphabet and each of the conventional arabic numerals is represented by a combination of raised dots peculiar to that letter or numeral. The field in which a single letter or numeral is represented is a matrix of six dots, three dots high by two dots wide. The code for the letters A through J are the same codes as for the numerals 1 through 9 and 0, so an extra code is provided to notify the reader that the code immediately following is to be interpreted as a numeral. A second extra code notifies the reader that the code immediately following is to be read as a capital letter.
The production of braille text thus is labor intensive and difficult, and learning to read braille text requires significant prowess and tactile acuity. Moreover, because the braille code bears little resemblance to the alphabet with which many who experience a loss of vision are familiar, it is particularly inappropriate for those who lose their sight late in life, when the resources and motivation to learn braille may be inadequate.
Modifications and alternatives to braille have been proposed to improve readability. For example, U.S. Pat. No. 3,363,339 to Place discloses a new braille cell structure which uses non-uniform raised dots or embossments in regular braille locations, which enables the reader to identify the cell line or column to which a boss belongs, even when a row or column is blank. U.S. Pat. No. 43,197,889 to Micropoulou discloses an alternative tactile code to braille comprising forming the thirteen most frequently used consonants by upsetting from the surface of a sheet, patterns consisting of groups of projections in permutations and combinations of four, the projections being disposed at the corners of a square, while the remaining letters of the alphabet are similarly formed, but by patterns consisting of two groups placed side by side. Numbers are formed by patterns of two such groups, the pattern of the first group of which differs from the pattern of the first group of the two letter groups. However, even these codes bear little resemblance to the conventional Roman alphabet and Arabic numerals, and thus suffer from the same deficiencies as conventional braille.
In summary, no simple tactile code exists which bears resemblance to the conventional alphabet and numerals and is therefore appropriate for use by those without the physical resources or motivation to learn braille. It is the solution of these problems to which the present invention is directed.